// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/arguments-inl.h"
#include "src/base/macros.h"
#include "src/base/platform/mutex.h"
#include "src/conversions-inl.h"
#include "src/counters.h"
#include "src/heap/factory.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/runtime/runtime-utils.h"

// Implement Atomic accesses to SharedArrayBuffers as defined in the
// SharedArrayBuffer draft spec, found here
// https://github.com/tc39/ecmascript_sharedmem

namespace v8 {
namespace internal {

// Other platforms have CSA support, see builtins-sharedarraybuffer-gen.h.
#if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X

    namespace {

#if V8_CC_GNU

// GCC/Clang helpfully warn us that using 64-bit atomics on 32-bit platforms
// can be slow. Good to know, but we don't have a choice.
#ifdef V8_TARGET_ARCH_32_BIT
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpragmas"
#pragma GCC diagnostic ignored "-Watomic-alignment"
#endif // V8_TARGET_ARCH_32_BIT

        template <typename T>
        inline T LoadSeqCst(T* p)
        {
            return __atomic_load_n(p, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline void StoreSeqCst(T* p, T value)
        {
            __atomic_store_n(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T ExchangeSeqCst(T* p, T value)
        {
            return __atomic_exchange_n(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T CompareExchangeSeqCst(T* p, T oldval, T newval)
        {
            (void)__atomic_compare_exchange_n(p, &oldval, newval, 0, __ATOMIC_SEQ_CST,
                __ATOMIC_SEQ_CST);
            return oldval;
        }

        template <typename T>
        inline T AddSeqCst(T* p, T value)
        {
            return __atomic_fetch_add(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T SubSeqCst(T* p, T value)
        {
            return __atomic_fetch_sub(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T AndSeqCst(T* p, T value)
        {
            return __atomic_fetch_and(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T OrSeqCst(T* p, T value)
        {
            return __atomic_fetch_or(p, value, __ATOMIC_SEQ_CST);
        }

        template <typename T>
        inline T XorSeqCst(T* p, T value)
        {
            return __atomic_fetch_xor(p, value, __ATOMIC_SEQ_CST);
        }

#ifdef V8_TARGET_ARCH_32_BIT
#pragma GCC diagnostic pop
#endif // V8_TARGET_ARCH_32_BIT

#elif V8_CC_MSVC

#define InterlockedExchange32 _InterlockedExchange
#define InterlockedCompareExchange32 _InterlockedCompareExchange
#define InterlockedCompareExchange8 _InterlockedCompareExchange8
#define InterlockedExchangeAdd32 _InterlockedExchangeAdd
#define InterlockedExchangeAdd16 _InterlockedExchangeAdd16
#define InterlockedExchangeAdd8 _InterlockedExchangeAdd8
#define InterlockedAnd32 _InterlockedAnd
#define InterlockedOr64 _InterlockedOr64
#define InterlockedOr32 _InterlockedOr
#define InterlockedXor32 _InterlockedXor

#if defined(V8_HOST_ARCH_ARM64)
#define InterlockedExchange8 _InterlockedExchange8
#endif

#define ATOMIC_OPS(type, suffix, vctype)                                        \
    inline type ExchangeSeqCst(type* p, type value)                             \
    {                                                                           \
        return InterlockedExchange##suffix(reinterpret_cast<vctype*>(p),        \
            bit_cast<vctype>(value));                                           \
    }                                                                           \
    inline type CompareExchangeSeqCst(type* p, type oldval, type newval)        \
    {                                                                           \
        return InterlockedCompareExchange##suffix(reinterpret_cast<vctype*>(p), \
            bit_cast<vctype>(newval),                                           \
            bit_cast<vctype>(oldval));                                          \
    }                                                                           \
    inline type AddSeqCst(type* p, type value)                                  \
    {                                                                           \
        return InterlockedExchangeAdd##suffix(reinterpret_cast<vctype*>(p),     \
            bit_cast<vctype>(value));                                           \
    }                                                                           \
    inline type SubSeqCst(type* p, type value)                                  \
    {                                                                           \
        return InterlockedExchangeAdd##suffix(reinterpret_cast<vctype*>(p),     \
            -bit_cast<vctype>(value));                                          \
    }                                                                           \
    inline type AndSeqCst(type* p, type value)                                  \
    {                                                                           \
        return InterlockedAnd##suffix(reinterpret_cast<vctype*>(p),             \
            bit_cast<vctype>(value));                                           \
    }                                                                           \
    inline type OrSeqCst(type* p, type value)                                   \
    {                                                                           \
        return InterlockedOr##suffix(reinterpret_cast<vctype*>(p),              \
            bit_cast<vctype>(value));                                           \
    }                                                                           \
    inline type XorSeqCst(type* p, type value)                                  \
    {                                                                           \
        return InterlockedXor##suffix(reinterpret_cast<vctype*>(p),             \
            bit_cast<vctype>(value));                                           \
    }

        ATOMIC_OPS(int8_t, 8, char)
        ATOMIC_OPS(uint8_t, 8, char)
        ATOMIC_OPS(int16_t, 16, short) /* NOLINT(runtime/int) */
        ATOMIC_OPS(uint16_t, 16, short) /* NOLINT(runtime/int) */
        ATOMIC_OPS(int32_t, 32, long) /* NOLINT(runtime/int) */
        ATOMIC_OPS(uint32_t, 32, long) /* NOLINT(runtime/int) */
        ATOMIC_OPS(int64_t, 64, __int64)
        ATOMIC_OPS(uint64_t, 64, __int64)

        template <typename T>
        inline T LoadSeqCst(T* p)
        {
            UNREACHABLE();
        }

        template <typename T>
        inline void StoreSeqCst(T* p, T value)
        {
            UNREACHABLE();
        }

#undef ATOMIC_OPS

#undef InterlockedExchange32
#undef InterlockedCompareExchange32
#undef InterlockedCompareExchange8
#undef InterlockedExchangeAdd32
#undef InterlockedExchangeAdd16
#undef InterlockedExchangeAdd8
#undef InterlockedAnd32
#undef InterlockedOr64
#undef InterlockedOr32
#undef InterlockedXor32

#if defined(V8_HOST_ARCH_ARM64)
#undef InterlockedExchange8
#endif

#else

#error Unsupported platform!

#endif

        template <typename T>
        T FromObject(Handle<Object> number);

        template <>
        inline uint8_t FromObject<uint8_t>(Handle<Object> number)
        {
            return NumberToUint32(*number);
        }

        template <>
        inline int8_t FromObject<int8_t>(Handle<Object> number)
        {
            return NumberToInt32(*number);
        }

        template <>
        inline uint16_t FromObject<uint16_t>(Handle<Object> number)
        {
            return NumberToUint32(*number);
        }

        template <>
        inline int16_t FromObject<int16_t>(Handle<Object> number)
        {
            return NumberToInt32(*number);
        }

        template <>
        inline uint32_t FromObject<uint32_t>(Handle<Object> number)
        {
            return NumberToUint32(*number);
        }

        template <>
        inline int32_t FromObject<int32_t>(Handle<Object> number)
        {
            return NumberToInt32(*number);
        }

        template <>
        inline uint64_t FromObject<uint64_t>(Handle<Object> bigint)
        {
            return Handle<BigInt>::cast(bigint)->AsUint64();
        }

        template <>
        inline int64_t FromObject<int64_t>(Handle<Object> bigint)
        {
            return Handle<BigInt>::cast(bigint)->AsInt64();
        }

        inline Object ToObject(Isolate* isolate, int8_t t) { return Smi::FromInt(t); }

        inline Object ToObject(Isolate* isolate, uint8_t t) { return Smi::FromInt(t); }

        inline Object ToObject(Isolate* isolate, int16_t t) { return Smi::FromInt(t); }

        inline Object ToObject(Isolate* isolate, uint16_t t) { return Smi::FromInt(t); }

        inline Object ToObject(Isolate* isolate, int32_t t)
        {
            return *isolate->factory()->NewNumber(t);
        }

        inline Object ToObject(Isolate* isolate, uint32_t t)
        {
            return *isolate->factory()->NewNumber(t);
        }

        inline Object ToObject(Isolate* isolate, int64_t t)
        {
            return *BigInt::FromInt64(isolate, t);
        }

        inline Object ToObject(Isolate* isolate, uint64_t t)
        {
            return *BigInt::FromUint64(isolate, t);
        }

        template <typename T>
        struct Load {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index)
            {
                T result = LoadSeqCst(static_cast<T*>(buffer) + index);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        struct Store {
            static inline void Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                StoreSeqCst(static_cast<T*>(buffer) + index, value);
            }
        };

        template <typename T>
        struct Exchange {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = ExchangeSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        inline Object DoCompareExchange(Isolate* isolate, void* buffer, size_t index,
            Handle<Object> oldobj, Handle<Object> newobj)
        {
            T oldval = FromObject<T>(oldobj);
            T newval = FromObject<T>(newobj);
            T result = CompareExchangeSeqCst(static_cast<T*>(buffer) + index, oldval, newval);
            return ToObject(isolate, result);
        }

        template <typename T>
        struct Add {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = AddSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        struct Sub {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = SubSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        struct And {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = AndSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        struct Or {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = OrSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

        template <typename T>
        struct Xor {
            static inline Object Do(Isolate* isolate, void* buffer, size_t index,
                Handle<Object> obj)
            {
                T value = FromObject<T>(obj);
                T result = XorSeqCst(static_cast<T*>(buffer) + index, value);
                return ToObject(isolate, result);
            }
        };

    } // anonymous namespace

// Duplicated from objects.h
// V has parameters (Type, type, TYPE, C type)
#define INTEGER_TYPED_ARRAYS(V)         \
    V(Uint8, uint8, UINT8, uint8_t)     \
    V(Int8, int8, INT8, int8_t)         \
    V(Uint16, uint16, UINT16, uint16_t) \
    V(Int16, int16, INT16, int16_t)     \
    V(Uint32, uint32, UINT32, uint32_t) \
    V(Int32, int32, INT32, int32_t)

    // This is https://tc39.github.io/ecma262/#sec-getmodifysetvalueinbuffer
    // but also includes the ToInteger/ToBigInt conversion that's part of
    // https://tc39.github.io/ecma262/#sec-atomicreadmodifywrite
    template <template <typename> class Op>
    Object GetModifySetValueInBuffer(Arguments args, Isolate* isolate)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(3, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
        CONVERT_SIZE_ARG_CHECKED(index, 1);
        CONVERT_ARG_HANDLE_CHECKED(Object, value_obj, 2);
        CHECK(sta->GetBuffer()->is_shared());

        uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) + sta->byte_offset();

        if (sta->type() >= kExternalBigInt64Array) {
            Handle<BigInt> bigint;
            ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
                BigInt::FromObject(isolate, value_obj));
            // SharedArrayBuffers are not detachable.
            CHECK_LT(index, NumberToSize(sta->length()));
            if (sta->type() == kExternalBigInt64Array) {
                return Op<int64_t>::Do(isolate, source, index, bigint);
            }
            DCHECK(sta->type() == kExternalBigUint64Array);
            return Op<uint64_t>::Do(isolate, source, index, bigint);
        }

        Handle<Object> value;
        ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, value,
            Object::ToInteger(isolate, value_obj));
        // SharedArrayBuffers are not detachable.
        CHECK_LT(index, NumberToSize(sta->length()));

        switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
    case kExternal##Type##Array:                      \
        return Op<ctype>::Do(isolate, source, index, value);

            INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

        default:
            break;
        }

        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AtomicsLoad64)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(2, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
        CONVERT_SIZE_ARG_CHECKED(index, 1);
        CHECK(sta->GetBuffer()->is_shared());

        uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) + sta->byte_offset();

        DCHECK(sta->type() == kExternalBigInt64Array || sta->type() == kExternalBigUint64Array);
        // SharedArrayBuffers are not detachable.
        CHECK_LT(index, NumberToSize(sta->length()));
        if (sta->type() == kExternalBigInt64Array) {
            return Load<int64_t>::Do(isolate, source, index);
        }
        DCHECK(sta->type() == kExternalBigUint64Array);
        return Load<uint64_t>::Do(isolate, source, index);
    }

    RUNTIME_FUNCTION(Runtime_AtomicsStore64)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(3, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
        CONVERT_SIZE_ARG_CHECKED(index, 1);
        CONVERT_ARG_HANDLE_CHECKED(Object, value_obj, 2);
        CHECK(sta->GetBuffer()->is_shared());

        uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) + sta->byte_offset();

        Handle<BigInt> bigint;
        ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
            BigInt::FromObject(isolate, value_obj));

        DCHECK(sta->type() == kExternalBigInt64Array || sta->type() == kExternalBigUint64Array);
        // SharedArrayBuffers are not detachable.
        CHECK_LT(index, NumberToSize(sta->length()));
        if (sta->type() == kExternalBigInt64Array) {
            Store<int64_t>::Do(isolate, source, index, bigint);
            return *bigint;
        }
        DCHECK(sta->type() == kExternalBigUint64Array);
        Store<uint64_t>::Do(isolate, source, index, bigint);
        return *bigint;
    }

    RUNTIME_FUNCTION(Runtime_AtomicsExchange)
    {
        return GetModifySetValueInBuffer<Exchange>(args, isolate);
    }

    RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(4, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
        CONVERT_SIZE_ARG_CHECKED(index, 1);
        CONVERT_ARG_HANDLE_CHECKED(Object, old_value_obj, 2);
        CONVERT_ARG_HANDLE_CHECKED(Object, new_value_obj, 3);
        CHECK(sta->GetBuffer()->is_shared());
        CHECK_LT(index, NumberToSize(sta->length()));

        uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) + sta->byte_offset();

        if (sta->type() >= kExternalBigInt64Array) {
            Handle<BigInt> old_bigint;
            Handle<BigInt> new_bigint;
            ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
                isolate, old_bigint, BigInt::FromObject(isolate, old_value_obj));
            ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
                isolate, new_bigint, BigInt::FromObject(isolate, new_value_obj));
            // SharedArrayBuffers are not detachable.
            CHECK_LT(index, NumberToSize(sta->length()));
            if (sta->type() == kExternalBigInt64Array) {
                return DoCompareExchange<int64_t>(isolate, source, index, old_bigint,
                    new_bigint);
            }
            DCHECK(sta->type() == kExternalBigUint64Array);
            return DoCompareExchange<uint64_t>(isolate, source, index, old_bigint,
                new_bigint);
        }

        Handle<Object> old_value;
        Handle<Object> new_value;
        ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, old_value,
            Object::ToInteger(isolate, old_value_obj));
        ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, new_value,
            Object::ToInteger(isolate, new_value_obj));
        // SharedArrayBuffers are not detachable.
        CHECK_LT(index, NumberToSize(sta->length()));

        switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype)                      \
    case kExternal##Type##Array:                                           \
        return DoCompareExchange<ctype>(isolate, source, index, old_value, \
            new_value);

            INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

        default:
            break;
        }

        UNREACHABLE();
    }

    // ES #sec-atomics.add
    // Atomics.add( typedArray, index, value )
    RUNTIME_FUNCTION(Runtime_AtomicsAdd)
    {
        return GetModifySetValueInBuffer<Add>(args, isolate);
    }

    // ES #sec-atomics.sub
    // Atomics.sub( typedArray, index, value )
    RUNTIME_FUNCTION(Runtime_AtomicsSub)
    {
        return GetModifySetValueInBuffer<Sub>(args, isolate);
    }

    // ES #sec-atomics.and
    // Atomics.and( typedArray, index, value )
    RUNTIME_FUNCTION(Runtime_AtomicsAnd)
    {
        return GetModifySetValueInBuffer<And>(args, isolate);
    }

    // ES #sec-atomics.or
    // Atomics.or( typedArray, index, value )
    RUNTIME_FUNCTION(Runtime_AtomicsOr)
    {
        return GetModifySetValueInBuffer<Or>(args, isolate);
    }

    // ES #sec-atomics.xor
    // Atomics.xor( typedArray, index, value )
    RUNTIME_FUNCTION(Runtime_AtomicsXor)
    {
        return GetModifySetValueInBuffer<Xor>(args, isolate);
    }

#undef INTEGER_TYPED_ARRAYS

#else

    RUNTIME_FUNCTION(Runtime_AtomicsLoad64)
    {
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AtomicsStore64) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsExchange) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsAdd) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsSub) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsAnd) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsOr) { UNREACHABLE(); }

    RUNTIME_FUNCTION(Runtime_AtomicsXor) { UNREACHABLE(); }

#endif // V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 \
    // || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X

} // namespace internal
} // namespace v8
